JavaScript must be enabled in order for you to use Knowledgebase Manager Pro. However, it seems JavaScript is either disabled or not supported by your browser. To use Knowledgebase Manager Pro, enable JavaScript by changing your browser options, then try again.
Learn more.

Introduction

BIND 9.11.0 is a new feature release of BIND, still under development.
This document summarizes new features and functional changes that
have been introduced on this branch. With each development
release leading up to the final BIND 9.11.0 release, this document
will be updated with additional features added and bugs fixed.

Download

The latest versions of BIND 9 software can always be found at
http://www.isc.org/downloads/.
There you will find additional information about each release,
source code, and pre-compiled versions for Microsoft Windows
operating systems.

Security Fixes

None.

New Features

Added rndc python module.

Added support for DynDB, a new interface for loading zone data
from an external database, developed by Red Hat for the FreeIPA
project. (Thanks in particular to Adam Tkac and Petr
Spacek of Red Hat for the contribution.)

Unlike the existing DLZ and SDB interfaces, which provide a
limited subset of database functionality within BIND —
translating DNS queries into real-time database lookups with
relatively poor performance and with no ability to handle
DNSSEC-signed data — DynDB is able to fully implement
and extend the database API used natively by BIND.

A DynDB module could pre-load data from an external data
source, then serve it with the same performance and
functionality as conventional BIND zones, and with the
ability to take advantage of database features not
available in BIND, such as multi-master replication.

New quotas have been added to limit the queries that are
sent by recursive resolvers to authoritative servers
experiencing denial-of-service attacks. When configured,
these options can both reduce the harm done to authoritative
servers and also avoid the resource exhaustion that can be
experienced by recursives when they are being used as a
vehicle for such an attack.

fetches-per-server limits the number of
simultaneous queries that can be sent to any single
authoritative server. The configured value is a starting
point; it is automatically adjusted downward if the server is
partially or completely non-responsive. The algorithm used to
adjust the quota can be configured via the
fetch-quota-params option.

fetches-per-zone limits the number of
simultaneous queries that can be sent for names within a
single domain. (Note: Unlike "fetches-per-server", this
value is not self-tuning.)

Statistics counters have also been added to track the number
of queries affected by these quotas.

Added support for dnstap, a fast,
flexible method for capturing and logging DNS traffic,
developed by Robert Edmonds at Farsight Security, Inc.,
whose assistance is gratefully acknowledged.

To enable dnstap at compile time,
the fstrm and protobuf-c
libraries must be available, and BIND must be configured with
--enable-dnstap.

A new utility dnstap-read has been added
to allow dnstap data to be presented in
a human-readable format.

New statistics counters have been added to track traffic
sizes, as specified in RSSAC002. Query and response
message sizes are broken up into ranges of histogram buckets:
TCP and UDP queries of size 0-15, 16-31, ..., 272-288, and 288+,
and TCP and UDP responses of size 0-15, 16-31, ..., 4080-4095,
and 4096+. These values can be accessed via the XML and JSON
statistics channels at, for example,
http://localhost:8888/xml/v3/traffic
or
http://localhost:8888/json/v1/traffic.

A new DNSSEC key management utility,
dnssec-keymgr, has been added. This tool
is meant to run unattended (e.g., under cron).
It reads a policy definition file
(default: /etc/dnssec.policy)
and creates or updates DNSSEC keys as necessary to ensure that a
zone's keys match the defined policy for that zone. New keys are
created whenever necessary to ensure rollovers occur correctly.
Existing keys' timing metadata is adjusted as needed to set the
correct rollover period, prepublication interval, etc. If
the configured policy changes, keys are corrected automatically.
See the dnssec-keymgr man page for full details.

Note: dnssec-keymgr depends on Python and on
the Python lex/yacc module, PLY. The other Python-based tools,
dnssec-coverage and
dnssec-checkds, have been
refactored and updated as part of this work.

(Many thanks to Sebastián
Castro for his assistance in developing this tool at the IETF
95 Hackathon in Buenos Aires, April 2016.)

The serial number of a dynamically updatable zone can
now be set using
rndc signing -serial numberzonename.
This is particularly useful with inline-signing
zones that have been reset. Setting the serial number to a value
larger than that on the slaves will trigger an AXFR-style
transfer.

When answering recursive queries, SERVFAIL responses can now be
cached by the server for a limited time; subsequent queries for
the same query name and type will return another SERVFAIL until
the cache times out. This reduces the frequency of retries
when a query is persistently failing, which can be a burden
on recursive serviers. The SERVFAIL cache timeout is controlled
by servfail-ttl, which defaults to 1 second
and has an upper limit of 30.

The new rndc nta command can now be used to
set a "negative trust anchor" (NTA), disabling DNSSEC validation for
a specific domain; this can be used when responses from a domain
are known to be failing validation due to administrative error
rather than because of a spoofing attack. NTAs are strictly
temporary; by default they expire after one hour, but can be
configured to last up to one week. The default NTA lifetime
can be changed by setting the nta-lifetime in
named.conf. When added, NTAs are stored in a
file (viewname.nta)
in order to persist across restarts of the named server.

The EDNS Client Subnet (ECS) option is now supported for
authoritative servers; if a query contains an ECS option then
ACLs containing geoip or ecs
elements can match against the address encoded in the option.
This can be used to select a view for a query, so that different
answers can be provided depending on the client network.

The EDNS EXPIRE option has been implemented on the client
side, allowing a slave server to set the expiration timer
correctly when transferring zone data from another slave
server.

A new masterfile-style zone option controls
the formatting of text zone files: When set to
full, the zone file will dumped in
single-line-per-record format.

dig +ednsopt can now be used to set
arbitrary EDNS options in DNS requests.

dig +ednsflags can now be used to set
yet-to-be-defined EDNS flags in DNS requests.

dig +[no]ednsnegotiation can now be used enable /
disable EDNS version negotiation.

dig +header-only can now be used to send
queries without a question section.

dig +zflag can be used to set the last
unassigned DNS header flag bit. This bit is normally zero.

dig +dscp=value
can now be used to set the DSCP code point in outgoing query
packets.

dig +mapped can now be used to determine
if mapped IPv4 addresses can be used.

serial-update-method can now be set to
date. On update, the serial number will
be set to the current date in YYYYMMDDNN format.

dnssec-signzone -N date also sets the serial
number to YYYYMMDDNN.

named -L filename
causes named to send log messages to the
specified file by default instead of to the system log.

The rate limiter configured by the
serial-query-rate option no longer covers
NOTIFY messages; those are now separately controlled by
notify-rate and
startup-notify-rate (the latter of which
controls the rate of NOTIFY messages sent when the server
is first started up or reconfigured).

The default number of tasks and client objects available
for serving lightweight resolver queries have been increased,
and are now configurable via the new lwres-tasks
and lwres-clients options in
named.conf. [RT #35857]

Log output to files can now be buffered by specifying
buffered yes; when creating a channel.

delv +tcp will exclusively use TCP when
sending queries.

named will now check to see whether
other name server processes are running before starting up.
This is implemented in two ways: 1) by refusing to start
if the configured network interfaces all return "address
in use", and 2) by attempting to acquire a lock on a file
specified by the lock-file option or
the -X command line option. The
default lock file is
/var/run/named/named.lock.
Specifying none will disable the lock
file check.

rndc delzone can now be applied to zones
which were configured in named.conf;
it is no longer restricted to zones which were added by
rndc addzone. (Note, however, that
this does not edit named.conf; the zone
must be removed from the configuration or it will return
when named is restarted or reloaded.)

rndc modzone can be used to reconfigure
a zone, using similar syntax to rndc addzone.

rndc showzone displays the current
configuration for a specified zone.

Added server-side support for pipelined TCP queries. Clients
may continue sending queries via TCP while previous queries are
processed in parallel. Responses are sent when they are
ready, not necessarily in the order in which the queries were
received.

To revert to the former behavior for a particular
client address or range of addresses, specify the address prefix
in the "keep-response-order" option. To revert to the former
behavior for all clients, use "keep-response-order { any; };".

The new mdig command is a version of
dig that sends multiple pipelined
queries and then waits for responses, instead of sending one
query and waiting the response before sending the next. [RT #38261]

To enable better monitoring and troubleshooting of RFC 5011
trust anchor management, the new rndc managed-keys
can be used to check status of trust anchors or to force keys
to be refreshed. Also, the managed-keys data file now has
easier-to-read comments. [RT #38458]

An --enable-querytrace configure switch is
now available to enable very verbose query tracelogging. This
option can only be set at compile time. This option has a
negative performance impact and should be used only for
debugging. [RT #37520]

A new tcp-only option can be specified
in server statements to force
named to connect to the specified
server via TCP. [RT #37800]

The nxdomain-redirect option specifies
a DNS namespace to use for NXDOMAIN redirection. When a
recursive lookup returns NXDOMAIN, a second lookup is
initiated with the specified name appended to the query
name. This allows NXDOMAIN redirection data to be supplied
by multiple zones configured on the server or by recursive
queries to other servers. (The older method, using
a single type redirect zone, has
better average performance but is less flexible.) [RT #37989]

The following types have been implemented: CSYNC, NINFO, RKEY,
SINK, TA, TALINK.

A new message-compression option can be
used to specify whether or not to use name compression when
answering queries. Setting this to no
results in larger responses, but reduces CPU consumption and
may improve throughput. The default is yes.

A read-only option is now available in the
controls statement to grant non-destructive
control channel access. In such cases, a restricted set of
rndc commands are allowed, which can
report information from named, but cannot
reconfigure or stop the server. By default, the control channel
access is not restricted to these
read-only operations. [RT #40498]

When loading a signed zone, named will
now check whether an RRSIG's inception time is in the future,
and if so, it will regenerate the RRSIG immediately. This helps
when a system's clock needs to be reset backwards.

Feature Changes

The ISC DNSSEC Lookaside Validation (DLV) service is scheduled
to be disabled in 2017. A warning is now logged when
named is configured to use this service,
either explicitly or via dnssec-lookaside auto;.
[RT #42207]

The timers returned by the statistics channel (indicating current
time, server boot time, and most recent reconfiguration time) are
now reported with millisecond accuracy. [RT #40082]

Updated the compiled-in addresses for H.ROOT-SERVERS.NET
and L.ROOT-SERVERS.NET.

ACLs containing geoip asnum elements were
not correctly matched unless the full organization name was
specified in the ACL (as in
geoip asnum "AS1234 Example, Inc.";).
They can now match against the AS number alone (as in
geoip asnum "AS1234";).

When using native PKCS#11 cryptography (i.e.,
configure --enable-native-pkcs11) HSM PINs
of up to 256 characters can now be used.

NXDOMAIN responses to queries of type DS are now cached separately
from those for other types. This helps when using "grafted" zones
of type forward, for which the parent zone does not contain a
delegation, such as local top-level domains. Previously a query
of type DS for such a zone could cause the zone apex to be cached
as NXDOMAIN, blocking all subsequent queries. (Note: This
change is only helpful when DNSSEC validation is not enabled.
"Grafted" zones without a delegation in the parent are not a
recommended configuration.)

Update forwarding performance has been improved by allowing
a single TCP connection to be shared between multiple updates.

By default, nsupdate will now check
the correctness of hostnames when adding records of type
A, AAAA, MX, SOA, NS, SRV or PTR. This behavior can be
disabled with check-names no.

Added support for OPENPGPKEY type.

The names of the files used to store managed keys and added
zones for each view are no longer based on the SHA256 hash
of the view name, except when this is necessary because the
view name contains characters that would be incompatible with use
as a file name. For views whose names do not contain forward
slashes ('/'), backslashes ('\'), or capital letters - which
could potentially cause namespace collision problems on
case-insensitive filesystems - files will now be named
after the view (for example, internal.mkeys
or external.nzf). However, to ensure
consistent behavior when upgrading, if a file using the old
name format is found to exist, it will continue to be used.

"rndc" can now return text output of arbitrary size to
the caller. (Prior to this, certain commands such as
"rndc tsig-list" and "rndc zonestatus" could return
truncated output.)

Errors reported when running rndc addzone
(e.g., when a zone file cannot be loaded) have been clarified
to make it easier to diagnose problems.

When encountering an authoritative name server whose name is
an alias pointing to another name, the resolver treats
this as an error and skips to the next server. Previously
this happened silently; now the error will be logged to
the newly-created "cname" log category.

If named is not configured to validate
answers, then allow fallback to plain DNS on timeout even when
we know the server supports EDNS. This will allow the server to
potentially resolve signed queries when TCP is being
blocked.

Large inline-signing changes should be less disruptive.
Signature generation is now done incrementally; the number
of signatures to be generated in each quantum is controlled
by "sig-signing-signatures number;".
[RT #37927]

The experimental SIT option (code point 65001) of BIND
9.10.0 through BIND 9.10.2 has been replaced with the COOKIE
option (code point 10). It is no longer experimental, and
is sent by default, by both named and
dig.

The SIT-related named.conf options have been marked as
obsolete, and are otherwise ignored.

When dig receives a truncated (TC=1)
response or a BADCOOKIE response code from a server, it
will automatically retry the query using the server COOKIE
that was returned by the server in its initial response.
[RT #39047]

A alternative NXDOMAIN redirect method (nxdomain-redirect)
which allows the redirect information to be looked up from
a namespace on the Internet rather than requiring a zone
to be configured on the server is now available.

Retrieving the local port range from net.ipv4.ip_local_port_range
on Linux is now supported.

A new nsip-wait-recurse directive has been
added to RPZ, specifying whether to look up unknown name server
IP addresses and wait for a response before applying RPZ-NSIP rules.
The default is yes. If set to
no, named will only
apply RPZ-NSIP rules to servers whose addresses are already cached.
The addresses will be looked up in the background so the rule can
be applied on subsequent queries. This improves performance when
the cache is cold, at the cost of temporary imprecision in applying
policy directives. [RT #35009]

Within the response-policy option, it is now
possible to configure RPZ rewrite logging on a per-zone basis
using the log clause.

The default preferred glue is now the address type of the
transport the query was received over.

On machines with 2 or more processors (CPU), the default value
for the number of UDP listeners has been changed to the number
of detected processors minus one.

End of Life

Thank You

Thank you to everyone who assisted us in making this release possible.
If you would like to contribute to ISC to assist us in continuing to
make quality open source software, please visit our donations page at
http://www.isc.org/donate/.